DE10211600A1 - Monolithic ceramic material used as, e.g. all-active catalysts and catalyst supports, comprises micropores, mesopores and/or macropores and is at least partially decomposable under physiological conditions - Google Patents

Abstract

A monolithic ceramic material comprising micropores, meso pores, and/or macropores, is new. It is at least partially decomposable under physiological conditions. An Independent claim is included for producing a monolithic ceramic material comprising bringing a precursor material, water-soluble polymer, an amphiphilic substance and a hydrolysis catalyst into contact with one another, inducing the sol-gel transition of the mixture, at least partially removing and replacing the solvent in the gel or at least partially removing or replacing the solvent, drying the green body, and calcining the dried green body at no more than most 500 degreesC at any point.

Description

The present invention relates to decomposable monolithic ceramic Materials with at least bimodal pore structure, in particular with micro and Mesopores or meso and macropores or micro, meso and macropores, as well as with metallic centers in the pores. The invention relates furthermore processes for the production of the materials according to the invention, and the use of the materials according to the invention and the materials which are produced in particular by one of the methods according to the invention catalysis and catalyst research as well as in medical technology and for the delayed delivery of active ingredients in the pharmaceutical Industry.

Generally, porous ceramic materials can be made according to a variety of Processes are prepared, wherein for the following presentation of the state of the Technology should be distinguished between three groups of materials according to are manufactured according to different processes: (i) materials with Micro and mesopores, (ii) materials with macro and mesopores, and (iii) Materials with micro, meso and macro pores. It is too early note that the porous materials in the processes according to (i) are only powder and not as a stable monolith and the porous materials according to the Processes (ii) and (iii) are not decomposable.

Porous ceramic materials with micro and mesopores, especially those made using amphiphilic substances in sol-gel processes are described, for example, in the following review article: D. M. Dabbs and I. A. Aksay, Ann. Rev. Phys. Chem. 51 (2000) 601-622. This Although materials have well-defined micro- and mesopores, they are only available as powder. The publication explicitly points out that "a necessary requirement for eventual commercial Application [of such mesostructures] in the formation of controlled moldings and Structures in the form of continuous thin films, fibers and monoliths " lies, the size of these forms "beyond the microscopic Particle size that has been synthesized "should be.

An optically isotropic and transparent monolith can, at least temporarily, Using a liquid crystal phase as a template in a sol-gel process can be obtained (see, for example, K.M. McGrath et al., Langmuir 16 (2000) 398-406), however, the monolithic silicate structure when dried into a powder decays. The use of surface-active agents also leads analogously ("surfactants") according to the prior art, such as ionic surface-active agents, to structures that occur during drying and / or Calcining disintegrates (see e.g. C.H. Ko et al., Microporous and Mesoporous Materials 21 (1998) 235-243). Poor dimensional stability, d. H. a powder Morphology, is even more pronounced for the well-known MCM-41 materials, which were first developed in 1992 in Mobil research laboratories.

In general, micro- and mesoporous structures can be particularly advantageous generate and vary when using the sol-gel method instead of the conventional one ionic surfactants non-ionic block copolymers be used. Here are in particular the work of G. D. Stucky and his Group (see e.g. D. Zhao et al., Science 279 (1998) 548-552). In In this process, amphiphilic triblock copolymers act as templates for the Pore formation and ultimately determine the porosity of the silicon framework. The Scaffolding is carried out in a sol-gel process by hydrolyzing a silicate Precursor material ("precursor") built. The mesoporous formed Structures show well-defined Bragg reflections in the X-ray powder diffractogram, especially in the small angle range. This leaves a high mark The degree of order on mesoscopic length scales is conclusive during calcination (see e.g. P. Yang et al., Nature 396 (1998) 152-155). The main advantage of these methods is that block Copolymers - in contrast to conventional surfactants - Allow a practically continuous variation of the pore parameters in situ during synthesis. This can be done, for example, by setting the Quantity ratios, the composition, the molecular weight or the molecular architecture of the block copolymers happen in the blend. The disadvantage, however, is that, according to the state of the art, in all Processes involving these block copolymers do not receive macropores and in particular that this porous material is powdery and is not a monolithic material.

Another class of sol-gel methods is based on the use of water-soluble polymers as template formers. In contrast to the aforementioned Processes result in materials with mesopores and macropores, however, no micropores. A major advantage of these materials lies in the fact that monolithic moldings and not only powder are now available are. In this context, the publications of To call Nakanishi and colleagues. For example, in WO 95/03256 the manufacture of porous monolithic materials using macro Mesopores described. These materials are available through the hydrolysis of Silicate precursor materials with subsequent sol-gel condensation in the Presence of water-soluble polymers, such as poly (ethylene oxides), (PEO).

The main process features of the synthesis of porous monolithic Ceramics according to Nakanishi are (i) the solvent exchange between acidic and basic solvent that contributes significantly to pore size and pore size distribution of the mesopores can be controlled in a targeted manner, and (ii) calcining the green body obtained after drying high temperatures, d. H. at at least 600 ° C. This calcining step is essential for solving the problem according to the invention set out in WO 95/03256, namely the provision of environmentally resistant, hardened glass-like Columns, especially for applications in high pressure Liquid chromatography (HPLC) are tailor-made. According to this procedure Silicate columns manufactured as Chromolith ™ from Merck (Darmstadt, Germany) or by EM Science (Gibbstown, New Jersey, USA) or distributed.

A disadvantage of the Nakanishi method mentioned above is in particular the fact that the glassy monolith obtained is dimensionally stable, but is also inert to physiological environmental conditions (see the below given definition of this), especially not soluble in water or aqueous Solutions. This is particularly disadvantageous for the delayed and timed Delivery of active ingredients in pharmacy as well as the design of biodegradable or resorbable bioceramics in medical technology. The procedure according to the state of the art, this leads exclusively to not in human Body-degradable or active ingredient-releasing porous ceramic structures. Furthermore, the lack of micropores in the monoliths according to Nakanishi can be regarded as a shortcoming, since trimodal porous monoliths on this Synthesis route are not available.

The state of the art also generally includes materials catalytically active metal centers. The publications of To call company Fina, which also deals with solid, particulate Deal with metallocenes or catalyst systems based on metal salt solutions, which in particular for the polymerization and / or copolymerization of Olefins are suitable (see, for example, EP 0 573 403, WO 98/02236 or US 5 846 896). These documents demonstrate the general importance of active metal Centers, said centers for example by fixing Metallocenes can be obtained on a support material. In the field of In this context, scientific literature is also the work of J.- M. Basset and colleagues (see e.g. V. Vidal et al. Science 276 (1997) 99-102) call. However, the state of the art does not contain any indications such as those on metallic components in general or based on metallocenes Active centers in connection with the decomposable according to the invention monolithic material can be obtained.

The prior art also does not describe ceramic materials that are micro-, meso- and macroporous at the same time, and in particular none Materials that are also monolithic and under physiological conditions are decomposable. Furthermore, no method is contained in the prior art, which would be suitable for the production of such materials. For example, EP 0 978 313 A1 describe a trimodal porous material (micro, meso and Macropores), but this is only a composite material made of active carbon a silicate framework available, d. H. the trimodal pore structure is in the Received follow-up and not intrinsically and in situ during the Manufacturing process. Furthermore, this material is not a ceramic Material (see definition below) in the sense of the present Invention since active carbon is not a ceramic as an essential component Material defined.

The state of the art regarding the controlled and / or time delayed Delivery of active ingredients is essentially through conventional techniques coined, d. H. the pressing of tablets with slowly detachable components or the Encapsulation of the active ingredient in a shell that decomposes in the stomach (see here for example JP 63243036, in which the retention of active substances by Admixing silicates and cellulose is described, as well as US Pat. No. 5,869,102, which is similar to the compression of the active ingredient, colloidal silicates and microcrystalline cellulose). Obviously it is These are processes in which the active ingredient after the shell has decomposed and / or other ingredients in macroscopic amounts, d. H. in batches, is released, the release rate is essentially independent of active ingredient is used, and the local application and the release rate cannot be varied or controlled particularly precisely.

Accordingly, it is desirable and the goal of significant efforts Research and development, active ingredients in microscopic or mesoscopic Fix "cages" in a targeted and drug-specific manner and then into one predetermined time at a specific location (gastrointestinal tract, connective tissue in case of wound healing etc.) by releasing the cage structure. On such an approach is described, for example, in F. Caruso et al., Chem. Mater. 11 (1999) 3309-3314. This document deals with micro-voids that by coating colloidal spherical templates with nano-particles and polymers can be obtained. Such hollow microstructures can, in this Documentation initially only theoretically, for inclusion and then for targeted Release of active ingredients, cosmetic substances or dyes used become. However, these materials are clusters in Solution and not a monolith.

The general topic of the targeted delivery of protein and peptide Active substances ("PP drugs"), in particular via the oral route, d. H. through oral Admission and subsequent entry into the bloodstream via the gastrointestinal Tract, is for example in A. Sood and R. Panchagnula, Chem. Rev. 101 (2001) 3275-3303. For the present invention, in particular This document describes the approach of Interest, the absorption of PP agents from the gastrointestinal tract into the bloodstream with the help of nano-particles. In fact, it has been found that particles up to 5 µm in size without changing their properties and can be introduced into the bloodstream intact via the intestinal wall.

Finally, there is also a recently published manufacturing process of porous carbon-containing powders / crystallites using to name silicate templates. Thereby carbohydrate-containing substances or carbohydrates as precursor compounds in contact with one silicate template, e.g. B. MCM-48 and MCM-41 brought. After drying and The silicate template, e.g. B. using HF and / or NaOH are removed and there remains a carbon-containing or Whole carbon porous powder with the pore structure of the silicate template back. In particular, the following two Publications referenced: M. Kruk et al., J. Phys. Chem. B 104 (2000) 7960 and R. Ryoo, S.H. Joo and S.J. Jun, J. Phys. Chem B 103 (1999) 7743. After However, the prior art cannot use this method monolithic moldings can be obtained.

In summary, it can be said that it is monolithic ceramic materials with micro and mesopores exist as well as corresponding materials with meso and macro pores, but that no monolithic ceramic Materials exist that are dimensionally stable, but are still under physiological conditions, d. H. decompose especially in contact with water. Such Materials are of particular interest for the targeted and time-delayed Delivery of active ingredients and in medical technology.

There are still no monolithic ceramic materials according to the prior art known in the art that have pores at all three levels, d. H. in the Principle of the atomic level, the nano level and the micro level. Such hierarchical materials are of particular interest for the catalyst Research and nano-technology.

Finally, there are no known ceramic materials that have a have at least bimodal pore structure with active metallic centers and are both monolithic and decomposable.

Accordingly, an object of the invention is to provide a novel ceramic monolithic material, which is micro and Mesopores or via meso and macro pores or via micro, meso and Macropores, and which can be decomposed under physiological conditions should, d. H. especially for use in the pharmaceutical industry, the Medical technology that is suitable for the cosmetics and food industries. The The materials used must therefore, in particular, not be biocompatible be toxic and biodegradable. Another key feature for the Mass production of such materials is that the basic materials are as possible should be cheap and available in large quantities, d. H. that for example the Use of expensive block copolymers should be avoided. Farther it is part of the task according to the invention, the novel porous ceramic Material either in the actual sol-gel manufacturing process or in the Aftertreatment or both in such a way that modification within the pores there is at least one active metal center. It's part of the job in particular, to provide a way to reduce acidity and / or redox Vary the behavior of the porous monolith according to the invention.

The specific shape and / or size and / or pore structure of the Monoliths according to the invention are to be defined in the production process itself and not only in a subsequent processing step like it for example, when compacting a porous powder. The decomposable, however dimensionally stable monolith should also be characterized in that it is amorphous, d. H. that it has no grain boundaries between crystallites that would crumble of the material can lead. Such an amorphous structure manifests itself for example due to the lack of Bragg reflections in the X-ray diffractogram.

In particular, the object of the invention is also monolithic ceramic materials with mesopores, d. H. Pores with a diameter between 2 nm and 50 nm, at which the pore diameter can be specifically set and varied within a wide range. Pores of this Diameters are of particular importance for applications of the Nanotechnology.

The object of the invention is achieved in that a dimensionally stable and coherent monolithic ceramic material is provided, which is essentially a hardened but not fully set, d. H. as an at least partially water-soluble agglomeration of nano- Particles can be viewed. The nano-particles build in connected framework, preferably a silicate framework. On a complementary level, the coherent nano-particles define a continuous, d. H. channel-like, network of micro, meso (= nano) or macro pores, d. H. material-free cavities.

Such a material can be obtained by various sol-gel processes, which are essentially characterized by the fact that at least one scaffold Precursor material ("precursor"), at least one for hydrolysis of the precursor Material suitable substance and at least one water-soluble polymer be put together. The addition of an amphiphile is optional, but constitutes a particularly important embodiment. The so obtained Mixing is then at least one sol-gel transition, a step of Solvent exchange and a drying step subjected. Jen after Embodiment is a subsequent to the drying step Calcination step required, the temperature of the calcination step so must be chosen so that the material sets, but not to an inert, glassy body hardens, d. H. that the material is still under in any case physiological conditions remains at least partially decomposable. The incorporation metallic active centers can either (i) in the sol-gel process Production of the material according to the invention by (co-) hydrolysis of decomposable precursor materials containing metals, or by (ii) contacting the green body according to the invention or the appropriate calcined material with easily hydrolyzable precursor compounds, which contain metals, in particular also of metallocenes, in one Post-treatment step. About the type and quantity of those imported according to (i) and / or (ii) active metal centers can then, as in the task according to the invention required both the acidity of the entire porous material and its redox Behavior can be set freely. The setting of these two parameters is included in particular possible independently of one another, since the two methods (i) and (ii) to introduce active metal centers on different principles are based and thus the acidity and redox behavior differ influence.

Below are those for understanding and interpreting the present Invention given essential definitions.

Of particular importance for the characterization of the invention Materials is its morphology, i.e. H. the property that the material is not considered Powder should be present, but in the form of a coherent shaped body, which is referred to as a monolith in the sense of the present invention. According to the invention, monoliths are intended as a coherent shaped body in all extend three spatial directions over at least one millimeter each. in the In principle, the monolith can take any shape, i. H. for example Plates, chopsticks, balls (beads, pellets), as well as any conceivable geometric shape. In particular, monoliths can also have complex shapes have, such as notches on the outer sides, with the aim of Transport and / or flow properties to improve the monolith. In In a practical embodiment, rods of 5 mm in diameter and a length of 5 to 10 mm.

Under a ceramic material in the sense of the present invention understood any material that has a higher after the drying step Proportion (in percent by weight) of inorganic constituents than organic components. Organic constituents are used according to the invention understood all components that are exclusively compounds with carbon and optionally contain nitrogen, hydrogen or oxygen. All other Compounds are considered inorganic components, especially such constituents that are known in chemistry textbooks as "organometallic" or "Silicon-organic" compounds are called.

Porous materials in general are u. a. by their pore size, Pore size distribution, type of pores present side by side, wall thickness of the pores surrounding scaffold, and characterized by their pore volume (porosity). With regard to the pore size, a distinction is made between microporous Materials, mesoporous materials as well as macroporous materials. The terms "Microporous", "Mesoporous" and "Macroporous" are used in the context of the present Invention as used in Pure Appl. Chem., 45 (1976) p. 79 are defined, namely as pores whose diameter is above 50 nm (macroporous) or is between 2 nm and 50 nm (mesoporous) or below 2 nm (microporous).

The pore size distribution can be narrow or wide, unimodal (a dominant diameter), bimodal (two pore types of different sizes lie side by side, with the mean pore sizes wider than the sum of the two Half-widths apart) or trimodal (three pore types different sizes exist side by side, with the mean pore sizes in each case adjacent pore types are greater than the sum of the corresponding two Half-widths apart). The pore size distribution (pore size distribution; PSD) can be obtained, for example, by adsorption measurements. in the In the case of the present invention, the pore size distribution can be determined by a Gaussian bell curve can be approximated well. The maximum of Bell curve gives the average pore size. The full width at half maximum, i.e. H. the width of the Function at half height between baseline and maximum, is a measure of the width of distribution. For most applications, the tightest possible Pore size distribution aimed for.

Due to inaccuracies in the measurement methods for determining Pore sizes becomes the assignment of pore types within an error bar of two Half-widths made. For example, measurements for one of the materials according to the invention have an average pore diameter of approximately 1 μm (1000 nm) is at a half-width of half a micrometer. in this connection it is clearly macro pores. At the same time it is found in the same Material another pore type with an average pore diameter of 20 nm and a half-width of 10 nm, i.e. H. in this case lie clearly Mesopores before. Finally there is a third pore type, the pore diameter is determined to 3 nm with a half-width of one nanometer and at according to the error given above, the assignment to micropores is possible. In any case, this material is a material with trimodal pore structure, since all three mean pore diameters are significantly wider than the sum of the relevant half-widths are in each case apart.

Porous materials with multimodal, i.e. H. at least with bimodal Pore size distribution is also called hierarchical. different Pore sizes are typically associated with different transport behavior. So z. B. macropores especially for "macroscopic" transport processes such as viscous or diffusive mass transport, whereas in the case dominated by mesopore interface diffusion and capillary effects, and in Micropores only activated transport takes place. hierarchical Pore structures therefore require hierarchical transport processes. So you can for example, molecules in micropores can be located in one place for a long time, then but when activating or dissolving the micropores quickly by capillary or diffusive transport in meso- or macropores transported away from this location become. Such a mechanism is for example local and temporal Localized drug delivery in pharmaceutical applications from Interest. A hierarchical pore structure is also corresponding for catalytic ones Systems interesting in which the quick delivery and removal of educts and Products for the catalytically active centers that are in micropores with high Surface are distributed through meso- and macroporous transport channels.

The term "decomposable" in the sense of the present invention refers to a Dissolving and / or decomposing the structural substance of the porous monolithic ceramic material under physiological conditions. physiological Conditions are all conditions as they exist in a living organism, can occur especially in the human organism, especially in aqueous solution, in salty aqueous solution, in acidic aqueous solution, in alkaline aqueous solution, and especially in the mouth Saliva, in body exudates and fumes, and in particular in sweat, as well as in all body secretions, especially in mucus, as well still in the gastric fluid, in the intestinal tract, in blood or blood plasma, in connective or muscle tissue as well as in bone or cartilage tissue.

The novel monolithic ceramic material in the sense of the present Invention is characterized in that it is at least bimodal and that it is at least partially decomposable under physiological conditions, the The term "decomposable" is to be understood as defined above. In a preferred one Embodiment contains the at least bimodal material micro and mesopores or meso and macropores or micro, meso and macropores, the last case is particularly preferred.

In a further preferred embodiment, the material according to the invention is characterized in that in X-ray examinations in the small-angle range, ie in the angular range from one degree to 5 degrees (when using a commercially available X-ray source, ie a conventional X-ray tube or a rotating anode, the Cu-K _α - Radiation emitted), has no Bragg reflections. Bragg reflections are understood to mean the sharp peaks known to the person skilled in the art, that is to say a few half-widths wide, which indicate the presence of long- or medium-range order and which can be used to index two- or three-dimensional ordered structures. Such Bragg reflections are found for the micro- and mesoporous materials available according to the prior art (see, for example, D. Zhao et al., Science 279 (1998), page 549), but not in the case of the materials according to the invention.

The material according to the invention is particularly distinguished in that that at no point in its pretreatment, manufacture and / or After-treatment has been heated above 500 ° C. This ensures that the Material not completely into a glass-like material or a glass ceramic fully hardened, which would then be inert against the at least partial decomposition physiological conditions. The fact that the material of the invention not during its pretreatment, manufacture and / or post-treatment 500 ° C may not be excluded, that the material of the invention at any time during its use, especially in catalytic applications exposed to a temperature higher than 500 ° C lies.

• - die Makroporen sind zu durchgehenden Transport-Kanälen verbunden, innerhalb derer Stofftransport von einer Seitenfläche des Monolithen zu mindestens einer weiteren Seitenfläche stattfinden kann;
• - die Größe der Makroporen, repräsentiert durch den mittleren Porendurchmesser in einer Fehlergrenze von plus/minus zwei Halbwertsbreiten, liegt zwischen 50 nm und 1000 µm, bevorzugt zwischen 0.1 µm und 100 µm, sowie besonders bevorzugt zwischen 0.5 µm und 30 µm;
• - die Größe der Mesoporen, repräsentiert durch den mittleren Porendurchmesser in einer Fehlergrenze von plus/minus zwei Halbwertsbreiten, liegt zwischen 5 nm und 50 nm und bevorzugt zwischen 10 nm und 40 nm;
• - die Größe der Mikroporen, repräsentiert durch den mittleren Porendurchmesser in einer Fehlergrenze von plus/minus zwei Halbwertsbreiten, liegt bevorzugt zwischen 0.5 nm und 4 nm und besonders bevorzugt zwischen 1 nm und 3 nm;.
• - die Größenverteilung der Mesoporen ist dergestalt, dass die Halbwertsbreite der Porengrößenverteilungsfunktion idealerweise nicht mehr als 100% der mittleren Porenbreite beträgt, wobei nicht mehr als 50% der mittleren Porenbreite besonders bevorzugt sind.
• - das erfindungsgemäße Material hat nach dem Trocknungs-Schritt einen höheren Anteil, gemessen in Gewichtsprozent, an anorganischen Bestandteilen als an organischen Bestandteilen.
• - das erfindungsgemäße Material enthält nach dem Trocknungs-Schritt als Hauptbestandteil, gemessen in Gewichtsprozent, Silizium und Sauerstoff.

In further embodiments, the monolithic ceramic porous material according to the invention is characterized in that it has at least one further property selected from the following group, or all of these properties:

• - The macropores are connected to continuous transport channels, within which the mass transfer from one side surface of the monolith to at least one further side surface can take place;
• - The size of the macropores, represented by the mean pore diameter within an error limit of plus / minus two half-widths, is between 50 nm and 1000 µm, preferably between 0.1 µm and 100 µm, and particularly preferably between 0.5 µm and 30 µm;
• - The size of the mesopores, represented by the mean pore diameter within an error limit of plus / minus two half-widths, is between 5 nm and 50 nm and preferably between 10 nm and 40 nm;
• - The size of the micropores, represented by the mean pore diameter in an error limit of plus / minus two half-widths, is preferably between 0.5 nm and 4 nm and particularly preferably between 1 nm and 3 nm.
• - The size distribution of the mesopores is such that the full width at half maximum of the pore size distribution function is ideally not more than 100% of the mean pore width, with no more than 50% of the mean pore width being particularly preferred.
• - After the drying step, the material according to the invention has a higher proportion, measured in percent by weight, of inorganic constituents than of organic constituents.
• - After the drying step, the material according to the invention contains silicon and oxygen as the main constituent, measured in percent by weight.

• A) Inkontaktbringen eines Vorläufer-Materials, eines wasserlöslichen Polymers sowie eines Hydrolyse-Katalysators;
• B) Induzieren des Sol-Gel-Überganges für das Gemisch aus (I);
• C) Entfernen und Austauschen des Lösungsmittels im Gel aus (II) oder Entfernen oder Austauschen des Lösungsmittels;
• D) Trocknen des aus (III) erhaltenen Grünkörpers;
• E) Kalzinieren des getrockneten Grünkörpers, wobei die Temperatur zu keinem Zeitpunkt über 500°C liegen darf.

The decomposable monolithic ceramic material according to the invention with at least a bimodal pore structure can be produced by any conceivable method which leads to the material mentioned above. In a preferred embodiment, it is produced by a method which comprises at least the following steps:

• A) contacting a precursor material, a water-soluble polymer and a hydrolysis catalyst;
• B) inducing the sol-gel transition for the mixture of (I);
• C) removing and replacing the solvent in the gel from (II) or removing or replacing the solvent;
• D) drying the green body obtained from (III);
• E) calcining the dried green body, the temperature at no time may be above 500 ° C.

This preferred embodiment is a sol-gel Method, d. H. polymerizing a molecular precursor material (precursor), typically characterized by hydrolysis of the precursor material with subsequent condensation, d. H. Forming an oxidic network. Depending on the condensation conditions, in particular depending on the pH, linear Polymers and long gel times or dense clusters or nano-particles and short gel times and of course all intermediate states can be set.

The materials (i) obtainable according to the invention are under physiological Conditions degradable, (ii) biodegradable, (iii) non-toxic and at all compatible with living organisms, as well as allow, at least in one Embodiment, (iv) the setting of a hitherto unknown for these materials trimodal pore structure.

The least to be used in the present embodiment Starting materials are: (i) a precursor material, (ii) one for the hydrolysis of the The aforementioned precursor material suitable substance, which in the following as Hydrolysis catalyst should be referred to, and (iii) a water-soluble polymer.

The precursor material provides the scaffold of the monolith to be produced in the sol-gel process by hydrolysis and condensation. In principle, all polymerizable substances with a low molecular weight can be used as precursor materials, and in particular: metal alkoxides, metal alkoxides with at least one non-hydrolyzable group; polymerizable metal salts and in particular metal halides, and metal hydroxides such as Al, Fe or Bi hydroxides, as well as coordination compounds with carboxyl or β-diketone ligands. "Metals" in the sense of the present invention are not only to be understood as the metallic conductors generally defined in textbooks, but also semi-metals and semiconductors, ie in particular B, Si, Ge, As, Se, Sb and Te. The alkoxides include, in particular, tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), tetrapropoxysilane (TPOS), and polymerized derivatives thereof; The halides include halides which are decomposable in aqueous solution, in particular chlorides such as SiCl ₄ , AlCl ₄ , TiCl ₄ , ZrCl ₄ , NbCl ₅ , TaCl ₅ , WCl ₆ or SnCl ₄ . In principle, it is also conceivable to use oligomeric precursor materials and organically modified silicates. The combination of two or more of the above substances is also included.

The use of TEOS as a precursor material is particularly preferred in the sense of the present connection. The common is more preferred Use of precursor materials that contain metals with silicate Precursor materials, such as TEOS in particular. As forerunners, the metals can generally contain all of the metal containing materials or metal-containing components or connections are used, the hydrolyzable alkoxides of Zr, Ti, Nb, Ta, Al, Sn and Pb are particularly preferred. It is also conceivable that the invention monolithic and decomposable ceramics using only Manufacture precursor materials that contain metals.

The use of hydrolyzable metal-containing components is one possible Way to the material according to the invention with at least one in the To achieve pore structure integrated metallic active center. Another one the possible route is given below as part of the aftercare. Under a "Metallic active center" in the sense of the present invention is any understood metallic or metal-containing aggregation, the at least one Contains metal atom and part of the inner and / or outer surface of the porous material according to the invention, d. H. can act catalytically.

A major advantage of this manufacturing method for an at least bimodal, porous and monolithic material is the ability to catalytic acidity to be able to specifically set active metallic centers. The metal can as a redox center in a more or less strongly basic or acidic environment act, for example determined by the ratio of TEOS to metal Alkoxide and / or the use of mixed metallic oxides or oxide Mixtures that are available in a wide range and in their concentration wide ranges can be varied. The catalytically active according to the invention Material with metal centers of controlled acidity / basicity is therefore e.g. B. conventional catalysts for oxidation reactions (such as Vanadium oxide on a support), because with these catalysts their inherent acidity leads to reduced selectivity and thus a subsequent enough large amount of basic additives must be added.

As a substance that leads to hydrolysis of the precursor material, i. H. as hydrolysis Catalyst, any substance can be used that the hydrolysis of the Forerunner material at least partially transported. These can be basic or be acidic substances, acidic substances in the sense of the present Invention are preferred because they are generally used to form condensed Clusters (nano-particles) lead. The only basic substances here are ammonia, Amines and ammonium hydroxide solutions called. As acidic substances Mineral acids such as nitric acid, sulfuric acid or hydrochloric acid called, as well organic acids such as acetic acids and especially fluoric acid (HF) and fluoride-containing solutions in general.

The use of dilute mineral acids, especially dilute ones Nitric acid, as well as dilute organic acids, especially dilute ones Acetic acid as a hydrolysis catalyst is particularly preferred in the sense of present invention.

Water-soluble polymers that meet the above requirements can be selected from the following group comprising neutral polymers, in particular poly (ethylene oxides), poly (vinyl pyrrolidones), poly (acrylamides), Polyols such as poly (ethylene glycols), polyols with formamide; ionic polymers, in particular polyacrylic acids, poly (alkali metal ion styrene sulfonates), poly (allylamines); and combinations of two or more of the aforementioned substances.

The use of polyethylene glycol (PEG) as a water soluble polymer is particularly preferred in the sense of the present invention.

The medium in which the aforementioned substances are combined to perform a sol-gel process is typically an aqueous one Medium which, if an acid is used as hydrolysis Catalyst is naturally acidic. Media, the alcohols or others Solvents and / or salts are also conceivable.

In addition to the above substances, at least added together have to be in the sol-gel process according to the invention to obtain material according to the invention, d. H. in addition to precursor material, hydrolysis Catalyst as well as water-soluble polymer, can optionally any other Auxiliaries, active ingredients or additives are added, insofar as these Do not adversely affect the gel process in such a way that this as Whole is no longer feasible. Such additional optional fabrics can are selected from the following group comprising: salts, buffers, fibers, especially cellulose; fillers; to be enclosed in the pores or in the framework fixed auxiliaries, active ingredients, additives, fragrances or flavors, in particular active pharmaceutical ingredients, enzymes, proteins, peptides; Swelling agents; Thickener; Dyes, pigments; metal-containing components, especially metal Ions or colloidal metals; Polymerization initiators or inhibitors; such as Combinations of at least two of the above substances.

The actual process for producing the material according to the invention is that the components listed above that are included in this Composition referred to as sol in a step (I) of contacting Stir given to each other and entered in a form, the Shape naturally determines the outer contours of the monolith. concrete Ratios of quantities present in the sol as well as absolute weights given in the exemplary embodiments. The framework is given below in which the proportions in the preferred Embodiments can move. The specification of such quantities is to be found in in no way other embodiments with different proportions from Exclude scope of protection, but is for illustration purposes only. This preferred proportions lead to a material which in the sense of Invention is dimensionally stable, d. H. results in a monolith, and which one at least partially connected channels of connected macroscopic pores. The preferred molecular weight of PEG has already been given above.

There is a content when using TEOS and nitric acid together with PEG of PEG in the range of 2 to 10 wt .-% based on the total weight preferred, 3 to 6% by weight being particularly preferred. With a PEG content below 3%, the macropores are largely isolated, whereas in a PEG content above 6% to break down the porous structure begins and individual particles can arise, d. H. the monolithic Properties are lost. By varying the PEG content between 3 and 6% by weight the diameter of the macropores can be varied from 1 to 80 µm, with a high PEG content a small diameter of the macropores equivalent.

The relative percentage of TEOS (again when using TEOS, PEG and Nitric acid) is specified using the so-called "r-value", which as the molar ratio of Si (from the TEOS) to water is given. For complete hydrolysis, which naturally requires four water molecules, This results in an r-value of 4. In a preferred embodiment lies the r-value of TEOS, based on the water content, between 10 and 20, where an r value that is between 12 and 18 is particularly preferred. With large r- Values, d. H. at low Si concentrations, particulate form Aggregates, whereas with small r values the macropores are isolated, d. H. the Transport channels are lost. The size of the macropores is determined by the Value also affected, though not as much as by varying the PEG content, and is between 80 µm (small r-value) and 5 µm (large r- Value).

It should be noted at this point that the size and interconnectivity of the macropores essentially due to the quantitative ratios PEG Total mass and TEOS is given to water, whereas the size of the mesopores essentially by the peculiarities of what is discussed below Solvent exchange is conditional.

After the components have been combined in the proportions mentioned above and the sol thus obtained has been introduced into the molding vessel, the sol is converted into a gel at temperatures which are in the range between 20.degree. C. and 80.degree. C., particularly preferably around 40.degree , When using TEOS, PEG and nitric acid in the above proportions, the _gel duration at 40 ° C is 4 to 6 hours (with the optional use of an amphiphile, such as the CTAB described below, the gel duration can be in the range of 4 hours to 12 hours).

Following this sol-gel transition, the gel is used for at least 48 Hours aged. Aging can occur at temperatures in the range of 20 ° C to 80 ° C take place, a temperature of 40 ° C in the sense of the present invention is particularly preferred. Aging in the sense of the invention is part of the sol- Gel transition, d. H. of step (II), and serves to (in the case the use of TEOS) to strengthen the silicate network and thus the Reduce or prevent cracking in the monolith.

A next step in the method according to the invention is step (III), namely that Removing the solvent or replacing the solvent. In the course aging and drying can remove solvents from the pores. The The solvent is exchanged by immersing the gel in an aqueous one Solution with an acidic or basic character, depending on whether it is acidic Solvent (here e.g. nitric acid) should be exchanged for a basic one or vice versa. Solvent exchange is essential for achieving one narrow pore size distribution of the mesopores, due to the dissolution and Redeposition of the matrix.

In the case of a gel obtained from TEOS, PEG and nitric acid, solvent exchange with ammonium hydroxide solution is a preferred one Embodiment. The lower the concentration of ammonium hydroxide, the more the mesopores become smaller. The size of the mesopores can therefore be determined by Varying the ammonium hydroxide concentration can be adjusted, whereby Concentrations of ammonium hydroxide from 0.01 mol / l to 2 mol / l are preferred. The average pore diameter of the mesopores is about 3 nm at 0.02 molar Solution and 16 nm with 2 molar solution, the values for the Pore diameters were obtained by mercury porosimetry.

A temperature in the range from 40 ° C. to 95 ° C. is preferred, one being Temperature in the range of 70 ° C to 90 ° C is particularly preferred. The lower the temperature, the smaller the mesopores. Typically the Solvent exchange is carried out for 5 to 10 hours, the times all the more become longer the lower the temperature. The volume of the liquid to be exchanged should be about 10 times larger than the volume of the monolith, in principle, however, any value for the volume ratio is conceivable as long as only the monolith is completely immersed in solvent. Regarding the In this context, solvent exchange will be the results of WO 95/03256 and N. Ishizuka et al., J. of Chromatography 797 (1998) 133-137 fully included in the present application.

After the solvent exchange, the monoliths are washed (e.g. with 0.1 M nitric acid and then with ethanol) and for three days dried about 60 ° C. This washing and drying step is in the sense of present invention as drying step (IV) viewed. The so obtained According to the invention, shaped bodies or monoliths are referred to as “green bodies” and can be used for the use according to the invention. In particular the green body can be subjected to all post-treatments, e.g. B. the Watering or contacting with catalytically active substances, (pharmaceutical) active ingredients, vitamins, enzymes, peptides, plant extracts, Phytotherapeutics, fragrances and flavors, auxiliaries, nutrients, cosmetic Substances, dyes, etc. The green body according to the invention is below physiological conditions, d. H. decomposable, especially in contact with water. d. H. All of the aforementioned substances can be used at a later date predetermined place are released again.

A preferred form of aftertreatment is that at least one Part of the inner surface that is formed by the micro, meso or macro pores or the resulting channels are given, are functionalized. It can be achieve, for example, that free hydroxyl groups of the structural substance be saturated by reaction, for example by esterification. In a particularly preferred embodiment can thus, for example, because of the hydroxyl groups actually hydrophilic inner surface at least partially made lipophilic.

In a further preferred embodiment of the aftertreatment, a (preferably easily) hydrolyzable precursor material that has at least one contains metallic component, with the material according to the invention (green body before calcination or moldings after calcination) in contact brought. The contacting can take place under all conditions that are mentioned below in connection with controlled atmospheres, d. H. in particular under vacuum or under an increase compared to the ambient pressure Print. The contacting can be done by watering or separating, the separation from the gas phase and / or the liquid phase taking place can. The contacting can be continuous, consecutive (i.e. the micropores first, then the meso- and / or macropores) or in any steps and / or intermediate states. After contacting the hydrolysis of at least part of the hydrolyzable material induced. All are for hydrolysis and as a metal-containing precursor material Suitable metal-containing substances that attach to the in the pores of the present OH groups and / or other conceivable material Connect functionalities, esterify with them or otherwise a stable bond to form. A bond is stable in the sense of the invention if it is among the conditions of use remain. The metal-containing precursors Materials can be from the above related precursor materials Generally named group of metal-containing precursor materials to be selected. Organometallic compounds, metal salts and colloidal Metals are preferred and metallocenes are particularly preferred.

The resulting active metal centers can, depending on the concentration of the metal-containing precursors brought into contact with the inner walls of the pores Material as well as depending on the functionality of the pores (density of the OH groups, reactivity of the OH groups, wettability of the pores etc.) principally occur in three different functional modifications: (a) as single active centers (single site contact), (b) as on the surface of a pore attached nano-particles and (c) with sufficient density at centers as a film. Of course, all intermediate states are also conceivable, e.g. B. linear chains, fractal paths or any combination of the above Modifications.

The statements made regarding the functional modification also apply analogously to Active centers, which, as described above, by (co-) hydrolysis of metal containing precursor materials.

In a further preferred embodiment, the invention at least bimodal silicate monolith in the course of a post-treatment step in contact with at least one carbon-containing precursor compound brought. In principle, the carbon-containing compound can be any substance that contains at least one carbon atom. There are alcohols and carbohydrates prefers. Every contact and / or application is the "contact" carbon-containing precursor compound with / on the porous silicatic Understand material. Soaking with a liquid solution, e.g. B. from Sucrose or furfuryl alcohol, preferred. In the sense of the present invention the at least bimodal silicate material according to the invention then acts as Template.

After impregnation, the now carbon-containing material according to the invention can be treated as it is, for example, in the two Publications M. Kruk et al., J. Phys. Chem. B 104 (2000) 7960 and R. Ryoo, S.H. Joo and S.J. Jun, J. Phys. Chem B 103 (1999) 7743. In this context these two publications are fully part of the reference present invention. Essentially, further processing is involved calcining at temperatures greater than 500 ° C, preferably at about 1000 ° C, under nitrogen and a subsequent coking under vacuum. Optionally can the silicate template can now be removed, for example by treating the Shaped body with HF and / or NaOH. After that, one essentially remains carbon-containing or entirely porous monolithic molded body, which has similar properties with regard to the pore structure has like the silicate molded body used as a template. As an advantage compared to the prior art, it should be mentioned that when using the inventive monolith as a template also a carbon-containing monolith arises, d. H. not just a porous powder.

When calcining, i.e. H. at step (V), the green bodies are in an open or burned in a controlled atmosphere. The temperature can between the drying temperature and 500 ° C. Temperatures between the drying temperature and 300 ° C are particularly preferred. The Calculation times depend on the desired degree of curing and can are between a few hours and a few days. The main purpose of the Calcining, in addition to further hardening, is in particular removing any unwanted organic components. Basically, it can Calcine before or after the treatment. Calcine before Aftercare affects u. a. the number of OH functionalities and thus below Aftertreatment under certain circumstances. For example, a reduced Number of OH functionalities also a reduced number of metal-containing ones Active centers.

Under controlled atmospheres in the sense of the present invention understood: inert gases, reducing atmospheres, for example forming gases containing hydrogen, hydrothermal conditions, especially vapors, oxidizing atmospheres, reactive gases, atmospheres under elevated or reduced pressure and all possible combinations and / or mixtures of atmospheres mentioned above.

• A) Inkontaktbringen eines Vorläufer-Materials, eines wasserlöslichen Polymers, einer amphiphilen Substanz, sowie eines Hydrolyse- Katalysators;
• B) Induzieren des Sol-Gel-Überganges für das Gemisch aus (I);
• C) Entfernen und Austauschen des Lösungsmittels im Gel aus (II) oder Entfernen oder Austauschen des Lösungsmittels;
• D) Trocknen des aus (III) erhaltenen Grünkörpers.

In a further, particularly preferred embodiment, not only is a monolithic ceramic decomposable material with a bimodal pore structure obtained, ie with macro and mesopores or with micro and mesopores, but a monolithic ceramic decomposable material with a trimodal pore structure, in particular with a macro, meso and micropores. All process steps are analogous to steps (I) to (IV) described above, with the exception that in step (I) a fourth component is added in addition to the precursor material, the hydrolysis catalyst and the water-soluble polymer an amphiphilic substance:

• A) contacting a precursor material, a water-soluble polymer, an amphiphilic substance, and a hydrolysis catalyst;
• B) inducing the sol-gel transition for the mixture of (I);
• C) removing and replacing the solvent in the gel from (II) or removing or replacing the solvent;
• D) drying the green body obtained from (III).

The amphiphilic substance has the task of another template for pore formation to make available (in addition to the water-soluble polymer, which for the Phase separation is responsible), due to the nature of this template the pores are formed at smaller diameters than the mesopores that arise due to the addition of the water-soluble polymer. In particular are in this way micropores, d. H. Pores of a few nanometers in diameter available. It should be emphasized in particular that in the method according to the invention the micropores during the production of the material according to the invention arise and not only introduced in a subsequent post-processing step become. The approach according to the invention thus ensures that the distribution of the Pores in the material is homogeneous. The amphiphilic substance is selected from the Group comprising block copolymers, in particular poly (alkylene oxide) triblock copolymers; surfactants, detergents and Soaps, and in particular non-ionic alkyl poly (ethylene oxides); lipids, phospholipids; as well as combinations of two or more of the above substances mentioned.

For the purposes of the present invention, the use of ionic surfactants, and in particular of hexadecyltrimethylammonium bromide, as an amphiphilic substance is particularly preferred. For the purposes of the present invention, all amphiphilic substances with a trimethylammonium bromide (TAB) unit and a carbon chain of any length are referred to as "CTAB". The number of carbon atoms can also be specified in individual cases, as in the present case, for. B. C ₁₆ TAB. If an amphiphilic substance is used, calcining at temperatures above 500 ° C. may be necessary if the complete removal of the organic amphiphiles is desired. If TEOS, PEG, nitric acid and CTAB are used as starting materials, a content of 0.01 to 5% by weight of CTAB is preferred and a content of 0.1 to 3% by weight is particularly preferred. By increasing the concentration of CTAB. In the specified range, both the mesopores are influenced, namely in the sense that their size decreases, and micropores are increasingly formed, the size of which extends from 1 nm to 5 nm and the number of which increases with increasing CTAB concentration.

Regarding the incorporation of active metal centers as well as regarding the Post-treatment steps apply to the trimodal porous according to the invention Material what was said above for the corresponding bimodal material.

Regarding the manufacture of carbon-containing or wholly from Carbon existing porous monolithic shaped bodies as a result of Aftertreatments of the trimodal porous silicate monolith according to the invention the above applies in full in connection with the bimodal Monoliths according to the invention said.

The monolithic ceramic material according to the invention can advantageously be used in catalytic applications are used. This applies in particular to those materials according to the invention which have active metal centers. As described above, these active metal centers can either be in the sol-gel Process or by post-treatment. Due to the Possibility of acidity and / or redox behavior of the active metal centers control, is the use of the catalysts according to the invention for (partial) Oxidation reactions are particularly preferred. Of course, it is also conceivable that material according to the invention as such, d. H. even without the presence of Active metals, is directly catalytically active, especially because of its hierarchical pore structure. All within the scope of the present invention described materials can be used directly as catalysts, as Use carrier materials for catalysts as well as in catalyst research.

In a preferred embodiment, the acidity and the redox potential or the acidity or the redox potential of the at least one metal-containing component together or independently of one another can be selected in the catalyst according to the invention with a metal-containing component by at least one of the measures mentioned below can be varied:
Concentration of the metal-containing precursor material relative to the non-metal-containing precursor material, type and composition of the metal-containing precursor material, density of the OH groups in the pores.

In related applications by exploiting the pore structure are characterized, the material according to the invention can be used as a molecular sieve, Ion exchanger or as a biological separator with a narrow cut-off criterion of molecular weight, and as an osmotic membrane. Applications as waveguides or substrates for optical sensors; Dry or biological sensors are also conceivable.

The use of the. Described above is of particular importance material according to the invention for time-delayed and time-controlled as well locally defined delivery of any substances, in particular of Dyes, cosmetic active ingredients, auxiliaries or additives, nutrients or Nutritional additives, feed or feed additives, fragrances and flavors. The delayed or timed, but in in any case locally well-defined delivery of pharmaceutically relevant Active substances in living organisms, especially in human Body particularly preferred.

In this context, the hierarchical pore structure is special Interest, since it is hereby possible to consecutively the material according to the invention loading and unloading. So z. B. the active ingredients, auxiliaries or additives that are smallest, first in the micropores, followed by larger active, auxiliary or Additives in the meso and / or macropores. When storing Mixtures, especially e.g. B. of plant extracts or phytotherapeutic agents even a "natural" separation of different ones Components result. It is also conceivable, in addition to the active, auxiliary or Additives that are typically molecular in nature and in micro or mesopores can be stored, additional cell components or larger peptide chains or similar in the macropores. It is also once again on the above described possibility pointed out, the inner surface in whole or in part functionalize, especially to make lipophilic. It is also conceivable Combine post-treatment and loading steps, d. H. for example, first store hydrophilic substances in the micropores, then the rest of the make the inner surface lipophilic and then a lipophilic substance store.

As already noted in the description of the prior art, there is one essential new development in active ingredients, especially those against susceptible to enzymatic decomposition and not per se through membranes absorbing PP active substances (proteins and peptides) in nano and micro particles to enclose and so for example through the intestinal wall into the blood stream convict. The material according to the invention is particularly suitable for such Applications since it can be viewed as an agglomeration of nano-particles can, the strength of the cohesion of the nano-particles by diverse Process parameters, such as PEG or TEOS content or degree of Hardening / drying / calcining, can be adjusted. The Agglomeration should be chosen so that the monolith until it enters the Darmflor remains intact and then disintegrates into the nanoparticles. Go there naturally lost the transport channels, but the active ingredient can still stay in meso- or micro-cavities of the particles and so in these Pass fragments into the bloodstream. There can also be the nano-particle dissolve and the active ingredient are released (without ever using chemical or physical barriers).

In this context, it is of particular interest that the PEG used the material according to the invention as such as a carrier for proteins is known, namely in the sense that proteins are used to increase the Transportability can be modified with PEG ("pegnology"). This leaves it for example Proteins appear homogeneous in step (I) incorporate material according to the invention by a mixture of PEG and PEG modified protein is used instead of pure PEG. The material can then solidify in the sol-gel process according to the invention and the monolith can be used directly as a protein supplier orally.

Furthermore, the use of the material according to the invention is biological degradable or resorbable (bio-degradable, i.e. not calcined or otherwise cured) preferred and the use as a biologically integrable ceramic material (bioactive, i.e. calcined, also known as bioglass) in the Medical technology, especially for bone reinforcement, for connective tissue Support and wound healing.

Regarding the above mentioned in the course of a post-treatment carbon-containing monoliths are in addition to those already mentioned Applications still preferred the following applications: (i) Use as Resorbent for substances, e.g. B. in poisoning phenomena in human Body, (ii) as hydrogen storage, both as storage material and such as well as a carrier material for another storage material.

Carbon-containing monoliths based on the silicate according to the invention Material as a template, and as mentioned above in the course of the Post-treatment of the silicate material according to the invention arise as Hydrogen storage or as a carrier for hydrogen storage particularly suitable as it have a large surface area, in particular due to the consecutive Pore structure. The use of these is particularly important in this context carbon-containing monoliths combined with highly disperse (finely divided) hydrides from Interest. The hydrides are the main and subgroup metals particularly preferred, e.g. B. Mg hydride which as a reversible hydrogen storage is known. It is also conceivable to use hydrides of semimetals and non-metals in the To use composite with the carbon-containing monolithic material, wherein mixed hydrides, d. H. Hydrides of the main and subgroup metals with the Semi-metals are particularly preferred. Among the mixed hydrides are for the hydrogen storage in particular the alanates of interest that for example contain Li, Al and hydrogen and typically in combination with carbon-containing materials, such as carbon nanotubes, used become. For the purposes of the present invention, these alanates are combined with the carbon-containing consecutive monolithic Material with at least bimodal pore structure used. Particularly preferred is a realization of the hydrogen storage, in which the hydrogen can be reversibly saved and released again.

Finally, it is also conceivable to use the materials according to the invention (with or without post-treatment) as thin films or as building blocks in Circuits. The use here in particular as dielectrics with high dielectric constant of interest because of a high pore volume correspondingly good electrical insulation, a fact that is particularly important for the miniaturization of circuits in which a "skipping" of Charge is always a problem.

The following are intended to manufacture and use the inventive Materials are illustrated using exemplary embodiments, without this the generality of the claims set forth in the present invention should be restricted.

example 1 Manufacture of a decomposable monolith with bimodal pore structure

In this example, the general synthetic route for making a decomposable monoliths with a bimodal pore structure. Limits, within which the proportion of individual components can be varied in described in the following examples.

In the first step, 0.7 g of polyethylene glycol (PEG) with the Molecular weight of 35,000 in 8.0 g of water and 0.81 g of 60% nitric acid dissolved. 6.5 g of TEOS are added to this mixture with stirring. The Sol is stirred until a clear solution is obtained and then in molds poured and gelled at about 40 ° C for 5 hours and for at least 48 Aged for hours at the same temperature.

To increase the degree of condensation in general and to control the size of the mesopores, the gel is subjected to a solvent exchange at 90 ° C. in 1 m ammonium hydroxide solution, for 9 hours. The volume of the solvent is about ten times the volume of the gel. After the solvent has been exchanged, the monoliths are washed with 0.1 M HNO ₃ solution and 25% ethanol.

In the drying step, the green bodies are dried for 3 days at 60 ° C. The monolith obtained afterwards shows all the characteristic properties of the material according to the invention, such as, for example, bimodal pore structure, Transport channels, absence of Bragg reflections. Subsequent to the Drying step, the monolith can be calcined at 450 ° C for 5 hours, the Temperature is ramped up by 1 K / min.

Example 2 Dependence of the pore structure on the molecular weight on PEG

The table given in this example shows how the pore structure (determined visually from SEM images and by measuring the porosity with Hg porosimetry) changes as a function of the molecular weight (MG) on PEG:
As can be seen from the table, the size of the macropores and their degree of crosslinking can be adjusted by varying the molecular weight of PEG.

Example 3 Dependence of the pore structure on the relative content of the PEG

The following table shows how the pore structure (determined visually from SEM images and measurements with Hg porosimetry) changes as a function of the relative content (measured in% by weight) of PEG when the molecular weight of PEG remains constant at 35,000 becomes.

As can be seen from the table, the size of the macropores and the degree of connection of the pores to the channels can be influenced by varying the relative proportion of PEG. The macropores of the sample K5 connected to channels are shown in FIG. 1 on the basis of an SEM (scanning electron microscopy) image on a scale of 1 cm ~ 30 μm.

Example 4 Dependence of the pore structure on the relative content of the TEOS

The following table shows how the pore structure (determined visually from SEM images and measurements with Hg porosimetry) changes as a function of the relative content (measured in% by weight) of TEOS.

Example 5 Dependence of the pore structure on the concentration of the Solvent in solvent exchange

The concentration of that used in the solvent exchange step Solvent (here: ammonium hydroxide replaces nitric acid) is special Significance for the size of the mesopores (determined by adsorption measurements with nitrogen). Here the change of essential pore parameters (Surface, pore volume, pore diameter) with the change of Concentration of ammonium hydroxide (1.0 m, 0.1 m and 0.01 m) at different Temperatures shown.

The sample is assigned to the corresponding temperature and concentration of ammonium hydroxide according to the following table


and the pore parameters for these samples are summarized in the following table:

Pore distribution functions for mesopores and macropores of decomposable monoliths, produced according to the general recipe described in Example 1 and subjected to a solvent exchange at 90 ° C. at different concentrations of ammonium hydroxide, are shown in FIG. 2. The horizontal x-axis describes the average pore diameter (in micrometers) and the vertical y-axis the measured proportion of pores at this diameter (measured in milliliters per gram). The solid line corresponds to a 2 m ammonium hydroxide solution, the dashed line corresponds to 0.2 m and the dotted line corresponds to a 0.02 m ammonium hydroxide solution. The diagram thus clearly shows that the size of the mesopores in particular can be set reproducibly via the concentration of ammonium hydroxide.

Example 6 Manufacture of a decomposable monolith with trimodal pore structure

0.62 g of PEG with a molecular weight of 35,000 and 5.5 g are used as sol Mixed water and 1.3 g of nitric acid. To this mixture, 5.05 g TEOS given and stirred until a clear solution is obtained.

At this point, 0.36 g of C ₁₄ TAB are added to the sol as amphiphiles. This means that in this example the PEG content is 4.84% by weight and the C ₁₄ TAB content is 2.78% by weight. The sol is then poured into molds and gelled at 40 ° C for 5 hours and then aged at 40 ° C for 48 hours.

Finally, the monolith is subjected to a solvent exchange at 90 ° C in 1 M ammonium hydroxide solution for 9 hours. The volume of the solvent is about ten times the volume of the gel. After the solvent has been exchanged, the green body is washed with 0.1 m HNO ₃ solution and 25% ethanol.

In the drying step, the green bodies are dried for 3 days at 60 ° C. and then calcined for 5 hours at 500 ° C., the temperature being raised with a ramp of 1 K / min. For monoliths with a trimodal pore structure, calcining is an essential step, since the C ₁₄ TAB can be removed quantitatively in this way.

Example 7 Varying the size of the micropores through the choice of the amphiphile

The monolith is produced exactly as described in Example 6, with the difference that C16TAB and C18TAB are now used instead of C14TAB. The influence of the choice of the amphiphile on the size of the micropores is shown in FIG. 3. The horizontal x-axis shows the pore diameter in nanometers and the vertical y-axis shows the pore volume to be assigned to the respective pore diameter in cubic centimeters per gram. Apparently, the diameter of the micropores can be shifted to smaller values by extending the aliphatic chain of the amphiphile.

The entire trimodal pore structure of a decomposable monolith, which was obtained with the addition of an amphiphile (here with C ₁₆ TAB), is shown by way of example in FIG. 4, the horizontal x-axis indicating the pore diameter in micrometers and the vertical y-axis the respective Proportion of pores in the total pore volume, measured in cubic centimeters per gram. The proportion of micro and mesopores with nitrogen adsorption was determined (dotted line) and the proportion of mesopores and macro pores with mercury porosimetry (solid line).

Furthermore, a small-angle X-ray diffractogram for the trimodal monolithic material with C ₁₆ TAB is shown in FIG. 5. The scattering angle 2 ist is entered in degrees on the horizontal x-axis (recorded at the energy of the Cu Kα line) and the relative scattering intensity in arbitrary units on the vertical y-axis. It can be clearly seen that only the envelope that is typical for small-angle scattering and falls from the primary beam (at 0 degrees) can be seen, but not the Bragg reflections that are otherwise typical for materials with mesopores (see discussion in the introduction). Thus, it is shown that the material of the present invention is actually disordered on all length scales.

Example 8 Materials according to the invention with active metal centers by co- Hydrolysis of TEOS with a metal alcoholate

The materials of the invention described in the example below were prepared according to the method described in example 1. The following table provides an overview of the quantities of feed used:

The niobium precursor used is a niobium alkoxide (niobium ethanolate). This was mixed with the TEOS and then to the nitric acid polymer solution added.

The table below gives an overview of the tests carried out and the properties of the materials after drying and calcining at 400 ° C.

The materials were checked for uniformity by means of X-ray fluorescence Niobium distribution examined. The following findings were found: (i) the in the Amounts of niobium introduced into the ceramic product recovered and (ii) the niobium introduced is uniform over the molded body distributed.

Molded articles produced by the process described above, in which the Niobium ethylate was replaced by tantalum ethylate, titanium ethylate and zirconium ethylate, also have uniform metal distributions in the silicate matrix.

Example 9 Materials according to the invention with active metal centers After-treatment of the porous monolith with a metal salt solution

A monolith (SiO ₂ ) produced according to Example 1 was activated in a Schlenk flask over a period of 12 h at 90 ° C. under an oil pump vacuum. After 12 hours the flask was cooled to room temperature and purged with oxygen and anhydrous argon. 10 ml of a 0.01 molar solution of vanadium (V) isopropoxide solution in anhydrous ethanol were added through a septum (= contacting). The monolith in the solution was heated to 50 ° C. for 3 hours, the solvent was then removed using a Schlenk frit and the monolith was evacuated at 90 ° C. for 12 hours. This material also shows an even loading with metallic centers and can optionally be calcined.

Claims (28)

1. Monolithic ceramic material with micro and mesopores or meso and macro pores or micro, meso and macro pores, characterized in that it is at least partially decomposable under physiological conditions and has at least one metallic active center integrated into the pore structure. 2. Material according to claim 1, characterized in that structural X-ray diffraction studies show no Bragg reflections in the Show small angle range. 3. Material according to claim 1 or 2, characterized in that at least one Part of the macropores and mesopores in the material or Macropores or mesopores transport channels running through the material form. 4. Material according to at least one of the preceding claims, characterized characterized in that the pore size is at least one of the properties from the includes the following group: the size of the macropores is between 0.1 µm and 100 microns, the size of the mesopores is between 5 nm and 50 nm, the The size of the micropores is between 1 nm and 3 nm. 5. Material according to at least one of the preceding claims, characterized characterized that after drying there is a higher proportion, measured in Percentage by weight of inorganic constituents than organic Ingredients. 6. Process for the production of a monolithic ceramic material with at least one metallic active center integrated into the pore structure and with micro and mesopores or meso and macro pores or micro, meso and macro pores which can be at least partially decomposed under physiological conditions, thereby characterized in that the process contains at least the following steps: A) contacting a precursor material, a water-soluble polymer, an amphiphilic substance, and a hydrolysis catalyst; B) inducing the sol-gel transition for the mixture of (I); C) removing and replacing the solvent in the gel from (II) or removing or replacing the solvent; D) drying the green body obtained from (III), and that the precursor material from (I) contains at least one metal-containing component. 7. The method according to claim 6, characterized in that after step (IV) an additional calcining step (V) A) Calcining the dried green body is carried out. 8. A method for producing a monolithic ceramic material with a metallic active center integrated into the pore structure and with mesopores and macropores, which is at least partially decomposable under physiological conditions, characterized in that the method contains at least the following steps: A) contacting a precursor material, a water-soluble polymer, and a hydrolysis catalyst; B) inducing the sol-gel transition for the mixture of (I); C) removing and replacing the solvent in the gel from (II) or removing or replacing the solvent; D) drying the green body obtained from (III), E) calcining the dried green body, the temperature at no time may be above 500 ° C., and that the precursor material from (I) contains at least one metal-containing component. 9. The method according to at least one of claims 6 to 8, characterized characterized that the precursor material is selected from the group comprising fully hydrolyzable alkoxides, alkoxides with at least one non-hydrolyzable group; Halides decomposable in aqueous solution, polymerizable metal salts, oligomeric precursor materials, organic modified silicates; Coordination compounds with carboxyl or β- Diketone ligand; as well as combinations of two or more of the above substances mentioned. 10. The method according to at least one of claims 6 to 9, characterized characterized in that the at least one metal-containing component of the precursor Materials is selected from the group comprising organometallic Compounds, metallocenes, metallic colloids, metal alkoxides as well Combinations of two or more of the above substances. 11. The method according to at least one of claims 6 to 10, characterized characterized in that the hydrolysis catalyst is selected from the group including basic substances such as ammonia, amines, ammonium ions Solutions; acidic substances such as mineral acids, organic acids, solutions containing fluoride; as well as combinations of two or more of the above substances mentioned. 12. The method according to at least one of claims 6 to 11, characterized characterized in that the water-soluble polymer is selected from the group uncharged and ionic polymers; as well as combinations or Mixtures of two or more of the aforementioned substances. 13. The method according to at least one of claims 6 to 12, characterized characterized in that the amphiphilic substance is selected from the group comprising block copolymers; surfactants, detergents, Soap; Lipids, phospholipids; as well as combinations of two or more hereof. 14. The method according to at least one of claims 6 to 13, characterized characterized in that as a precursor material TEOS or a metal alkoxide or TEOS and a metal alkoxide is used as a hydrolysis catalyst Nitric acid, as a water-soluble polymer PEG and as an optional amphiphilic Substance CTAB, and that the PEG content is in the range from 2 to 10% by weight, based on the total weight is that the molecular weight of PEG between 10,000 and 50,000 is the relative percentage of TEOS given given by the r value, in the range from 10 to 20, that the proportion of optional CTAB between 0.01 and 5 wt .-%, based on the total weight, and that the solvent for the Solvent exchange is ammonium hydroxide. 15. The method according to at least one of claims 6 to 14, characterized characterized in that the material according to the invention a post-treatment is subjected to, wherein the after-treatment can be selected from the following Group comprising: watering or contacting the monolithic ceramic material with catalytically active substances, organic Compounds or mixtures, or other auxiliaries or additives, the Functionalizing at least parts of the inner surface, the Lipophilisieren; the consecutive loading of the pores as well as any combination of two or more of the above steps. 16. The method according to claim 15, characterized in that the catalytic active substance for soaking or contacting is selected from the group comprising organometallic compounds, metallocenes, metallic colloids, metal salts, metal alkoxides and combinations of two or more of the aforementioned substances. 17. The method according to claim 15, characterized in that the at least a substance for soaking or contacting at least one contains carbon-containing precursor compound, said carbon-containing precursor compound contains at least one carbon atom. 18. The method according to claim 17, characterized in that the at least a carbonaceous precursor compound is selected from the Group of alcohols or carbohydrates. 19. The method according to claim 17 or 18, characterized in that the carbon-containing material according to the invention after soaking or Contacting is calcined at temperatures greater than 500 ° C under nitrogen, and then coked under vacuum. 20. The method according to claim 19, characterized in that the silicate Template by treating the shaped body with HF and NaOH or HF or NaOH is removed. 21. The method according to at least one of claims 15 to 20, characterized characterized in that the material according to the invention after the aftertreatment is calcined. 22. The method according to at least one of claims 6 to 21, characterized characterized in that the shape, size and pore structure of the invention Monolith is defined in the manufacturing process itself. 23. The method according to at least one of claims 6 to 16, characterized characterized by at least one of the measures selected from the following group the acidity and the redox potential or the acidity or the redox potential of the at least one metal-containing component in the material according to the invention varies together or independently of one another can: Relative concentration of the metal-containing precursor material on the non-metal-containing precursor material, type and composition of the metal-containing precursor material, density of the OH groups in the pores. 24. Use of the monolithic ceramic material according to at least one of claims 1 to 5 or of the monolithic ceramic material, obtainable by a process according to at least one of claims 6 to 23 as a full catalyst, as a catalyst support, as a molecular sieve, as biological separator with a narrow cut-off criterion regarding the Molecular weight, as an osmotic membrane and as a dielectric medium. 25. Use of the monolithic ceramic material according to at least one of claims 1 to 5 or of the monolithic ceramic material, obtainable by a process according to at least one of claims 6 to 23 for the time-delayed and time-controlled as well as locally defined delivery of dyes, cosmetic active ingredients, auxiliary or Additives, pharmaceutically relevant substances, proteins, peptides, Enzymes, herbal active ingredients, nutrients or nutritional additives, Feed or feed additives, fragrances and flavorings. 26. Use of the monolithic ceramic material according to at least one of claims 1 to 5 or of the monolithic ceramic material, obtainable by a process according to at least one of claims 6 to 23 as biodegradable or bioabsorbable or as biologically integrable ceramic material in medical technology, especially for bone reinforcement, connective tissue support and Wound healing. 27. Use of the monolithic carbonaceous material available according to a method according to at least one of claims 17 to 22 Storage material for hydrogen or as a carrier material for one Hydrogen storage. 28. Use of the monolithic carbonaceous material available after a method according to at least one of claims 17 to 22 in Compound with or doped with at least one reversible hydrogen storage medium, selected from the group of hydrides the main and Subgroup metals, the semimetal hydrides, the mixed hydrides, the alanates and mixtures of at least two substances thereof.